1. Field of the Invention
This invention relates to an improved apparatus for controlling the operation of an oral illumination system associated with a fluid driven or an electrically driven dental handpiece unit.
2. Prior Art
It is known that some dental handpiece units have associated therewith one or more fiber optic bundles which direct a beam of light to the region of a patient's tooth which is being drilled. See, for example, U.S. Pat. Nos. 2,539,828 to Goldis et al; 3,397,457 to Gosselin; 3,634,938 to Hutchinson; 3,638,013 to Keller; 3,683,503 to Klein; and 3,897,134 to Scrivo.
Other handpiece units have miniature lamps attached internally or externally at the turbine end of the handpiece to illuminate the area being drilled directly without the use of the fiber optic bundles. See U.S. Pat. No. 2,038,911 to Stutz et al; French Pat. No. 1,123,034 to Pestel; and German Pat. No. 853,494.
Prior art units provide light to the handpiece by:
(1) A MANUALLY OPERATED ON-OFF SWITCH OR (2) A HANGER POSITION SWITCH THAT SENSES WHETHER THE HANDPIECE IS INOPERATIVE (IN THE HANGER) OR IS BEING USED (IN THE DENTIST'S HAND). In the first case, operation of the switch may interrupt the dentist's normal operating technique by causing momentary loss of concentration. In the second case if the dentist wishes to examine the burr or turbine after removing the handpiece from the hanger, he may have to look into the fiber optic light or miniature lamp which is already on. Because the issuing light is substantially brighter than ambient room illumination, the dentist may momentarily be "dazzled" and may need to pause briefly before resuming work on the patient.
The apparatus of this invention solves the problem of momentary dazzle by providing means to illuminate the oral cavity just prior to the dentist inserting the drill of the handpiece into the patient's mouth.
The apparatus of this invention also allows the light to remain lit for a predetermined period of time after drilling has ceased thereby enabling the dentist, if desired, to examine the drilled area with the aid of the light emitted at the operative end of the handpiece. The predetermined period of time can be varied as desired, and after the light is automatically extinguished the dentist may examine or change the burr, etc.
The apparatus of this invention also allows the dentist to illuminate a patient's mouth using the light associated with the handpiece prior to drilling by providing means to turn on the light and maintain it on for a predetermined period of time.